(1) distillation: regular distillation of crude oil into gasoline, kerosene, diesel oil and other light fractions, followed by decompression distillation (residual pressure 10-100mmhg)when decompression distillate oil is separated, the remaining residue can be directly produced when it meets the road asphalt specifications. The bitumen obtained is also called straight-distillation bitumen is the main way to produce road asphalt.
(2) solvent precipitation method: non-polar low molecular paraffin solvents have different solubility for each component of the decompression residue, and the difference of solubility is used
The separation of different components can be realized, so the disadvantageous components of bitumen can be removed from the decompression residue, and the bitumen production can meet the specifications
This is solvent precipitation.
(3) emulsifying method: the surface tension of asphalt and water is very different, and they will not mix at room temperature or high temperature. But when the asphalt is centrifuged at high speed
The mechanical actions of cutting and pressing make it a particle with a particle size of 0.1~5 centile m and disperse to a surfactant (emulsifier -- stabilizer)
) in the water medium, because the emulsifier can be adsorbed on the surface of bitumen particles, the interfacial tension between water and bitumen can be reduced and the bitumen particles can be enabled
A stable dispersion system is formed in water, which is the emulsion of water containing oil. The dispersion system is tawny, asphalt is dispersed phase, water is continuous
Phase, good fluidity at room temperature. In a sense, emulsified asphalt "dilutes" the bitumen with water, thus improving its fluidity